his objective of this Mentored Research Scientist Development Award application is to obtain the training and research experience required for me to become a productive independent researcher investigating relationships between neuroimaging-based markers of brain structure and late-life cognitive decline. The application builds on my computational training in image processing to position me as an effective member of a multidisciplinary team that will be able to apply state-of-the-art neuroimaging methods to research questions related to cognitive decline while effectively interfacing with psychologists, pathologists, and other scientists with complementary expertise. The career development plan strengthens my foundation in image processing and supplements it with focused training in medical image acquisition, statistics and epidemiology, neuroanatomy, and psychology to make me a knowledgeable user of research tools from each of those areas. Training will be acquired through a structured program of formal coursework, focused meetings with area mentors, colloquia and seminars, and attendance of research meetings at a local and national level. The research plan develops the methodology required for large-scale study of relationships between imaging-based brain structure measures and cognitive decline, and applies the methodology to cohorts from population-based studies and an academic dementia clinic. The specific aims are to 1) investigate relationships between automated imaging-based measures of lateral ventricle structure and subsequent cognitive decline, 2) relate the structure of the lateral ventricles to the structure of periventricular structures, and 3) apply the automated image processing methodology developedfor the first two aims to large population-based cohorts with longitudinal imaging and cognition measures to cross-validate findings. The research and career development outlined in this application will leverage my unique computational skills into an effective career as an independent investigator able to contribute neuroimaging perspectives to our evolving understanding of the biological basis of late-life cognitive decline.